3-4 shift prob

This is a discussion on 3-4 shift prob within the Automatic Transmission forums, part of the Drivetrain category; Help please! heres the deal car was shifting funny took it in and had the 1-2 and 3-4 solenoids replaced ...

3-4 shift prob

Help please! heres the deal car was shifting funny took it in and had the 1-2 and 3-4 solenoids replaced and now it hits the rev limiter when shifting from 2nd to 3rd under wot. the shop said everthing looked good in the trans and they dont know whats causing it to do this. does anyone know whats going on with my trans and how do i fix it??? the trans has a yank 3500 stall and transgo shift kit.

programing

has the tranny be reprogramed to work with the 3500 stall , i have found when we ship trannys to people that those that us over a 2500 stall run into this problem from time to time , A good way to test this is in two ways ,
one if the shop your dealing with has a snapon or otc scanner they can look at the data stream to determine if in fact the 2-3 shift is being comanded , if its not then its a programing issue and you will need to get with someone who does programing , alternatly to rule out any trans problem such as a slipping 3-4 clutch pack would be if the shop has a device called a shafer shifter this plugs directly to the trans and allow you to selct which solinoids come on manually if its used to make that 2-3 shift and it occurs good its still a programing issue , however if its used and the 2-3 shift does not occur under throttle theres a 3-4 clutch issue .
hope this helps most well equipt tranny shops will have this test equipment but im betting on a programing issue since we have over the years had many calls after install of these high stall converters with this complaint even in cases where it was perfect with the lower stall converters ,
megamax

I dont think its the converter cause its been in the car for the last five years and worked great with no tune. I talked to a programer last night about this problem and he didnt think it was the comp cause it was acting fine before the soleniods where changed. any other thoughts on whats going on?

well i would goto the shop and do the two test i suggested in the prevoious they will determine one or the other , there is one more thing you had both shift solinoids replace (why?) and do you know what brand they were gm or aftermarket new or reman , the reason i as there is one more possibility particularly if theres been a shift kit installed and or the prograning has been used to raise line preasure , Thats solinoid flooding this is where though the solinod is working its not capablke of venting enough fluid to allow the shift when off , both solinods are off for thrid gear in the 4l60e , however if one is restricted or faulty or i had one instance of using aftermarket solinods i beleave they were fitxall bran and i could not get out of first at full throttle both solinoids on , because they could not vent enough fluild to allow valve stroke ,
However first i would do the snapon test wastching data to see if the shift is comanded , then if so i would do the shafer shifter tet and see if i ciould get the shift that way at full throttle , the shafter shifter is the real test since if if can make the shift (also note it has a place to control pcs preasure since your having only a full throttle shift issue it should be set to max on the tester ,)then it has to be a program issue if you cannot make the shift with it then its either a 3-4 clutch issue or as i mentioned earlier a solinoid issue .
megamax